In the American system of governance, the member of the majority in a chamber of the legislature (at the federal level, the House of Representatives or the Senate) who works to get his colleagues to vote the party line. During the impeachment votes, for example, Tom DeLay, via all manner of threats, including the cutoff of all-important campaign-finance assistance, got wavering Republicans to "do the right thing". Nice Guys rarely get the gig.

Also a fine dessert topping.